1. Field of the Invention
The present invention relates to a variable weight load generating apparatus where the weight exhibited by a viscous friction load and/or a resilient load may be continuously varied at will. The invention may be applied to, for example, the training of sportsmen or patients for improving their muscular power. The invention is also applicable to actuators for robots.
2. Prior Art
There has not been a variable weight load generating apparatus for use in improving the muscular power of sportsmen and patients. Thus, weight loads were implemented by using the weight of discrete objects. A proper weight is selected from different weights to provide a specific weight value. Selecting the proper weight from a variety of discrete weights is rather cumbersome and cannot provide a continuously variable weight. For example, load-applying apparatuses used in robot actuators are designed to hold and/or carry predetermined parts and objects with predetermined pressures or forces. However, the apparatuses are not adapted to continuously vary the holding pressures or weights, or to finely vary them under specific conditions.
The aforementioned prior art apparatuses are of the construction where the torque of a rotative drive source such as a motor, is merely transmitted by way of a friction element or clutch. Accordingly, loads are only transmitted in steps in a discontinuous manner. Thus, the prior art apparatuses find no application in muscular power training for athletes or patients under rehabilitation where stable and variable loads are required. In robotics, a holding or securing force is often required to be varied according to the shape and the nature of the workpieces. The prior art apparatuses are not suitable for this type of applications.